SAM7S256_14 Datasheet, PDF (143/775 Pages) ATMEL Corporation – ARM-based Flash MCU

21. SAM7 Boot Program
21.1
Description
The Boot Program integrates different programs permitting download and/or upload into the different memories of
the product.
First, it initializes the Debug Unit serial port (DBGU) and the USB Device Port.
SAM-BA^® Boot is then executed. It waits for transactions either on the USB device or on the DBGU serial port.
21.2 Flow Diagram
The Boot Program implements the algorithm shown in Figure 21-1 or Figure 21-2.
Figure 21-1. Boot Program Algorithm Flow Diagram with USB
No
Device
Setup
USB Enumeration
Successful ?
No
AutoBaudrate
Sequence Successful ?
Yes
Run SAM-BA Boot
Yes
Run SAM-BA Boot
Figure 21-2. Boot Program Algorithm Flow Diagram without USB
No
Device
Setup
AutoBaudrate
Yes
Sequence Successful ?
Run SAM-BA Boot
SAM7S Series [DATASHEET]
6175M–ATARM–26-Oct-12
143